Researchers from the University of Sheffield, in partnership with the Diamond Light Source, are leading the way in understanding slow transformations in nuclear waste materials. Their experiment has just reached a major landmark – 1000 days – the longest running synchrotron light experiment in the world.

The research led by Dr Claire Corkhill from the Department of Materials Science and Engineering, is using the world-leading capabilities at Diamond to investigate how cement materials used in nuclear waste disposal behave in the long-term. Monitoring changes in eight nuclear waste cement materials by measuring high resolution diffraction patterns on the I11-1 beamline at Diamond Light Source, the UK’s national synchrotron science facility. The research is a joint venture funded by the UK Government through the Science & Technology Facilities Council (STFC) in partnership with the Wellcome Trust. The results are being used to support the ongoing safety case development for UK Government policy to dispose of nuclear waste in a deep geological disposal facility.

“These cements are being used to safely lock away the radioactive elements in nuclear waste for timescales of more than 10,000 years, so it is extremely important that we can accurately predict the properties of these materials in the future,” explained Dr Corkhill. “The unique facility at Diamond has allowed us to follow this reaction in-situ, for 1000 days, and the data is already allowing us to identify particular phases that will safely lock away radioactive elements in 1000 years’ time, something we would otherwise not have been able to determine.”

Dr Corkhill is planning to return to Diamond to investigate the reaction of these phases with uranium, technetium and plutonium on one of the X-ray absorption spectroscopy beamlines.

Professor Neil Hyatt, Director of the Immobilisation Science Laboratory and Co-Investigator, said: “We are very excited to be selected to participate as the first ever users in this world-leading capability and want to thank everyone at the Diamond Light Source, especially Dr Chiu Tang, Dr Sarah Day and Dr Claire Murray from I11, for all their support in bringing our experiments to fruition and being the custodians of our samples for 1000 days. We are pleased that this 1000 day landmark cements our long-term collaboration between the University of Sheffield and the scientists at the Diamond Light Source.”